Photoperiod induction of fertile oestrus and changes in LH and progesterone concentrations in yearling dairy goats (Capra hircus)

Bondurant, Robert; Darien, B. J.; Munro, Coralie; Stabenfeldt, G. H.; Wang, P.

doi:10.1530/jrf.0.0630001

Cited by 41 publications

(15 citation statements)

References 12 publications

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“…Asher et al (1988a) reported that, in fallow deer, the duration of the LH surge extended over approximately 15 h. Thus, in these three species of deer, the LH surge exhibits a similar dynamic change following progesterone decline. In this respect, deer would appear to exhibit a longer LH surge than those reported for cattle (Rahe et al, 1980;Peters, 1984;Walters & Schallenberger, 1984) or goats (BonDurant, 1981) but similar to that for sheep (McLeod et al, 1982(McLeod et al, , 1983McLeod & Haresign, 1984).…”

Section: Discussionsupporting

confidence: 58%

Effect of age and time of day on the timing of the surge in luteinizing hormone, behavioural oestrus and mating in red deer hinds (Cervus elaphus)

Argo

Loudon

1992

Reproduction

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The oestrous cycles of fourteen red deer hinds (six yearling; eight more than 2 years old) were synchronized during the early breeding season by removal of a progesterone-containing intravaginal device and blood samples were taken at intervals of 3 h commencing 13 or 25 h later and continued for 54 h. The controlled internal drug release devices (CIDRs) were removed at 08:00 h (group 1; three yearlings and four adults) or 12 h later at 20:00 h (group 2; three yearlings and four adults). There was no significant effect of time of removal of CIDR on the interval to the onset of oestrus (group 1, 34.5 +/- 4.05 h; group 2, 42.14 +/- 7.8 h) on the time of peak concentration (group 1, 41.81 +/- 5.69 h; group 2, 41.71 +/- 7.81 h) or on duration of the luteinizing hormone (LH) surge (group 1, 15.00 +/- 0.95 h; group 2, 14.57 +/- 0.78 h). The six yearling animals exhibited oestrus and LH surge significantly later than the adults (55 +/- 4.2 versus 32 +/- 6.3 h for the LH surge for yearling and adult females, respectively). In a further experiment, 20 hinds were synchronized during the breeding season by removal of CIDR at two times of day 12 h apart and placed with a stag. Mating took place at a mean time of 42.1 +/- 2.4 h and 37.0 +/- 1.3 h later in the two groups. There was no significant effect of time of removal of CIDR upon time to onset of oestrus.(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Discussionsupporting

confidence: 58%

Effect of age and time of day on the timing of the surge in luteinizing hormone, behavioural oestrus and mating in red deer hinds (Cervus elaphus)

Argo

Loudon

1992

Reproduction

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“…In most instances, these increases in progesterone only last 1-3 days and attain a maximum of about 1 ng/ml. Transient, low-amplitude increases in progesterone have also been observed before the first cycle at puberty in lambs (Foster & Ryan, 1979;Berardinelli et al, 1980;Keisler et ai, 1983;Foster et al, 1986), heifers (González-Padilla et al, 1975) and primates (Dierschke et al, 1974;Foster, 1977), after pulsatile administration of GnRH to anoestrous ewes (Legan et al, 1985a;Hunter et ai, 1986), after a ram-induced LH surge in anoestrous ewes (Pearce et al, 1985), at the end of post-partum anoestrus in cows (Pope et ai, 1969), and at onset of the breeding season in dairy goats (BonDurant et al, 1981). They are therefore a common phenomenon of the initiation of cyclicity in at least these 4 species.…”

Section: Methodsmentioning

confidence: 99%

Changes in LH pulse frequency and serum progesterone concentrations during the transition to breeding season in ewes

I’Anson

Legan²

1988

Reproduction

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Summary. To characterize the changes in LH pulse frequency during the transition to breeding season, LH pulse patterns and serum progesterone profiles were determined in 8 intact ewes from mid-anoestrus to the early breeding season. Overall, 8 increases in LH pulse frequency were observed and these were restricted to 5 ewes. Of the 8 increases, 7 occurred during the 4 weeks before the first cycle, 5 of them within 1 week after a pulse frequency typical of anoestrus (0\p=n-\2per 8 h). Six of them occurred less than 1 week before either a full-length luteal phase (n = 2) or a 1\p=n-\3-day increment in progesterone (n = 4). Seven of these brief progesterone increases were observed in 6 ewes, 5 of them immediately preceding the first full-length luteal phase. These results are consistent with the hypothesis that the seasonal decrease in response to oestradiol negative feedback at the beginning of the breeding season causes an increase in GnRH, and thereby LH pulse frequency. In addition, they demonstrate that the first increase in tonic LH secretion occurs in < 1 week and, in most ewes, initiates either the first fulllength cycle or a transient increase in progesterone, the latter occurring more often.

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“…Also, photoperiod manipulation [2] and sudden introduction of males [14] induced estrus during the non-breeding season in goats. Pregnancy rates as high as 40-60% have been attained out of breeding season [7], and administration of equine chorionic gonadotropin has been shown to be necessary to get a satisfactory ovulatory response in anestrous goats [10].…”

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confidence: 99%

Induction of Estrus during the Non-Breeding Season in Egyptian Baladi Goats.

Medan

Shalaby

Sharawy

et al. 2002

The Journal of Veterinary Medical Science

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ABSTRACT. The induction of estrus during the non-breeding season was investigated in 100 Egyptian Baladi goats (Capra hircus). All animals assigned to treatments had low progesterone concentrations (<0.5 ng/ml) tested 2 times 10 days apart to confirm anestrous condition. Animals were assigned to three experimental groups. A group of animals received subcutaneous norgestomet ear implant for 11 days and a single i.m injection of PGF2α 24 hr before implant removal (group I; n=40). Second group of animals received subcutaneous norgestomet ear implant for 11 days and a single i.m injection of PGF2α 24 hr before implant removal and gonadotropin releasing hormone 24 hr after implant removal (group II; n=40). Third group of animals received no treatment (control group; n=20). The percentage of goats that showed estrous behavior during the first 72 hr after implant removal was 77.5, 85.0% and 10.0% in group I, group II and control group, respectively. The fertility rate was 57.5, 70.0% and 10.0% in group I, group II and control group, respectively. In conclusion, estrus can be induced in seasonally anestrous Egyptian Baladi goats using norgestomet and PGF2α and the injection of GnRH 24 hr after norgestomet implant removal synchronized ovulation in a higher percentage of goats. KEY WORDS: anestrus, caprine, induction of estrus.

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Photoperiod induction of fertile oestrus and changes in LH and progesterone concentrations in yearling dairy goats (Capra hircus)

Cited by 41 publications

References 12 publications

Effect of age and time of day on the timing of the surge in luteinizing hormone, behavioural oestrus and mating in red deer hinds (Cervus elaphus)

Effect of age and time of day on the timing of the surge in luteinizing hormone, behavioural oestrus and mating in red deer hinds (Cervus elaphus)

Changes in LH pulse frequency and serum progesterone concentrations during the transition to breeding season in ewes

Induction of Estrus during the Non-Breeding Season in Egyptian Baladi Goats.

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